A linear Di-coordinate boron radical cation.

The pursuit of di-coordinate boron radical has been continued for more than a half century, and their stabilization and structural characterization remains a challenge. Here we report the isolation and structural characterization of a linear di-coordinate boron radical cation, achieved by stabilizing the two reactive atomic orbitals of the central boron atom by two orthogonal π-donating and π-accepting functionalities. The electron deficient radical cation undergoes facile one-electron reduction to borylene and binds Lewis base to give heteroleptic tri-coordinate boron radical cation. The co-existence of half-filled and empty p orbitals at boron also allows the CO-regulated electron transfer to be explored. As the introduction of CO promotes the electron transfer from a tri-coordinate neutral boron radical to a boron radical cation, the removal of CO under vacuum furnishes the reverse electron transfer from borylene to yield a solution consisting of two boron radicals.

[Comparison of 3D C-arm fluoroscopy-based and CT-based navigation systems in the lumbar pedicle puncture: in vitro experiment on a cadaveric lumbar trunk specimen].

OBJECTIVE: To compare the accuracy and operating features of 3D C-arm fluoroscopy-based and CT-based navigation systems in the lumbar pedicle punctures. METHODS: A specimen of cadaveric lumbar trunk underwent lumbar pedicle punctures at the levels of L3, L4, and L5 under the guidance of the 3D C-arm fluoroscopy-based and CT-based navigation systems. During the procedure C-arm fluoroscopy was used to monitor the accuracy of the puncture. Generally, in comparison with the 3D C-arm fluoroscopy-based navigation system, the best operation route and protocol could be drawn up pre-operatively, matched registration needed to be renewed for each vertebra, and the images thus obtained were of high quality in CT-based navigation. RESULTS: Both navigation systems had excellent accuracy in the guidance of lumbar pedicle punctures, and had different operating features. CONCLUSION: Both navigation systems had its special advantages. The operating process of the 3D C-arm fluoroscopy-based navigation system was more convenient and rapid, and suitable for percutaneous vertebral puncture. CT based navigation system had clearer pictures, especially for the osteoporotic vertebral bodies, and it had less requirements for the equipments.